To the average homeowner, ordering lumber at the hardware store can be an intimidating process. They ask you questions about kiln dried and what grade of plywood. If you go into it knowing some of the terminology, you will be ordering lumber like a professional in no time.
Ordering Lumber Sizes
Lumber typically starts at 6 feet in length and moves up in increments of 2 feet. Small lumber yards may only have a few options but large lumber yards will stock lengths up to 20 feet long. Most lumber yards can also order longer lengths if you are building large structures and don’t want to join 20 foot boards.
For people looking to save some money, you can always buy longer boards and have the lumber yard cut it to length for you. One thing to be aware of is that lumber yards must provide you the stated board length or longer. It is not uncommon to get a board slightly longer than advertised. It’s free lumber…run with it and make something with those scraps!
One specialty length of board to be aware of is the “stud” length boards. These are 2x4s or 2x6s that are cut in order to account for the top plate and bottom plate of a wall framing. When these boards are used, it allows you to hang drywall most effectively by taking out the need to cut an 8 foot sheet. This saves a ton of labor and prevents wasted materials. It’s not every day you find something good for your wallet and the environment.
Framing lumber begins at 2 inches usually and goes up in 2 inch increments. Most lumber yards will carry lumber up to about 12 inches wide. It is the width of your lumber that determines how strong it is and how much weight it can really support. The longer the span you are covering, the thicker the board you will need.
Nominal Lumber Sizes
There is an important note on lumber sizing. Due to the milling and shrinking of lumber, softwood and framing lumber is sold according to nominal sizes. What that means is that a 2×4 does not measure 2 inches by 4 inches. Instead, it is more like 1-1/2 inches by 3-1/2 inches.
Nominal sizing is the most confusing aspect of ordering lumber. One thing to note, this is an industry standard and it isn’t a defect or the lumber yard trying to cheat you out of material. When you are ordering lumber, you have to be specific about what you want. If you want a board that truly measures 1 inch, you need to ask for it according to fractions. For example, a 5/4 board will typically measure about 1 inch thick.
Hardwood vs Softwood
So, here’s a fun fact: the terms hardwood and softwood don’t necessarily note if a wood is hard or soft. Instead, it indicates if the wood came from a conifer tree, a softwood, or a deciduous tree, a hardwood. When ordering lumber, it’s important to know the benefits of each. Softwoods tend to dent more easily than hardwoods and they tend to absorb moisture. Hardwoods are expensive and because they don’t grow as slowly, they are hard to find in large quantities.
Since softwoods are less expensive, they are easier to get in large quantities and make great moulding. Softwood, like pine, are also great for shelving if you need something simple. Not all softwoods are delicate though. For example, cedar is a great exterior wood option and very resistant to rot because of its natural tannins.
Hardwoods are commonly selected for furniture building due to their dimensional stability. Oak, maple, and hickory are all hardwoods that are used for everything from bookshelves to cupboards. Hardwoods are more expensive because they typically grow slower than softwood trees so don’t expect to get a ton of boards all at once. Don’t judge them by their name though: balsa is a hardwood by definition and it is found in abundance for inexpensive prices.
Ordering Lumber Grades
Lumber is graded for the overall quality of the board or sheet. They grade lumber based on every aspect, from the grain pattern and the number of knots to the color and general appearance. Sometimes a knot is not an issue (pun intended) but other times, it is vital to have lumber without knots, or clear.
Knots tend to make the lumber slightly less stable so it’s important that anything structural have closed knots if there are knots at all. Closed knots mean that there is a knot but you can’t see through the board. Straight, or vertical, grain is important if you want a stylish, expensive look to your board for finish work. For some great information on lumber grading, check out Art of Manliness and Woodworkers Source.
Green, Kiln Dried, and Pressure Treated Lumber
Green lumber is lumber that has been air dried. What that means is that the board is milled, or cut, and then stacked to dry. This is a less expensive way to purchase lumber because it requires less labor and facilities than other lumber.
Green lumber does tend to warp and twist, sometimes badly, as it dries. Wood was once alive as a tree and so it is subject to the stresses and tensions of the wood grain and cell structure of the tree it came from. If you need a board to stay straight, you need to be ordering lumber that is kiln dried. If you are framing for example, then you don’t want to use green lumber. If you are building a catio however, your cat probably won’t care if your lumber twists.
Kiln Dried Lumber
Kiln dried lumber is perfect if you want a board that will stay almost identical to how it is when you buy it: flat hopefully. This lumber is dried before it is milled to its final dimensions so the lumber you buy doesn’t change after it dries out, like the green lumber does. For structural purposes, you should always buy kiln dried lumber. For any finish millwork, from furniture to trim, you need to make sure the lumber is kiln dried or you may end up redoing it in a year.
Pressure Treated Lumber
Pressure treated lumber is not a specific type of wood but rather a treatment of the wood. To make a pressure treated board, holes are made along the board, which are obvious when you buy it, and then chemicals are forced into the wood through the holes using pressure. These chemicals keep the wood from rotting and make it last a long time but they do have some drawbacks.
If you are building garden beds, you want to make an educated decision about pressure treated lumber. This lumber used to have chemicals in it that would harm you if ingested. While it doesn’t now, some people still prefer cedar instead. Pressure treated lumber also requires specific fasteners that won’t break down in the chemicals, galvanized or stainless.
Natural Defects in Wood
- Bow–Bending in the direction of the grain
- Checks–Crack in the wood fiber partway through the board
- Closed/Tight Knot–A knot that has a center solidly in place
- Crook–When the board, laid flat, curves to the left or right along the grain
- Cupping–Bending across the grain direction
- Fungus–Different colors that indicate fungal infections in the tree
- Insect Bores–Holes that are caused by insects eating tunnels in the tree
- Open/Loose Knot–A knot that has a center missing or falling out
- Sap Pocket–A sign of injury in the tree where sap collected
- Split–Crack going all the way through the board running lengthwise
- Twist–Lengthwise spiraling of the board
- Wane–A piece of bark section that keeps the board from being square
Lumber Defects Aren’t All Bad
Not all defects are bad. Sometimes ordering lumber specifically for it’s defects allows you to get interesting styles and looks. For example, I am currently hoarding #3 pine boards. Specifically the #3 pine boards because this is the grade of a beetle bitten pine board. This particular defect results in streaks of blue and brown and it’s peppered with beetle bores. The combination creates incredible character in a board that is cheap and designated as basically trash.
There are so many details to ordering lumber that it can be mind boggling. You need to know what specific type of wood you want, hardwood or softwood. You also need to know what your main goal is if you need to pay for kiln dried lumber or if you can save some money and use green lumber. Once you’re done ordering lumber, you then need to select quality pieces and know what defects to look out for. Don’t hesitate to ask questions of the sales people or ask what a term means. It is vital that you get lumber that is appropriate for your project after all.